PestDex Details
Carpenter Ant
Camponotus pennsylvanicus
crawler
Large black ant that excavates wood to build nests. Major structural pest in MD/VA wooded areas.
How to Identify
- •Black, ½–⅝ inch long (largest ant in region)
- •Single node between thorax and abdomen
- •Winged swarmers appear in spring
- •Rustling sound in walls when active
Where Found
Nests in moist or decayed wood — siding, deck posts, roof eaves, hollow trees. Satellite colonies in walls if moisture present. Northern VA and Montgomery County MD have endemic populations.
Seasonality
Swarms March–May. Workers forage spring through fall. Dormant in winter cold.
Health & Property Risk
Structural damage. Excavates galleries in wood (doesn't eat it). Weakens framing, decks, and siding over years. Bites if disturbed but not venomous.
Prevention Tips
- •Fix roof leaks and gutter overflow
- •Replace water-damaged wood
- •Trim tree branches away from roof
- •Store firewood away from house
- •Seal cracks where utilities enter
Treatment Notes
Locate main nest (often outside) and satellite colonies. Non-repellent spray or dust in voids. Bait less reliable. Address moisture — they won't colonize dry wood.